SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '583c50dbc3fb456bd00f788bb0a793885b3c63ef4aa65d1850209735711f9ba5' 
  AND token = 'ZVZCs1wGLe4nSk78TraPSqzPHzssUK3qq5MZfgOtiD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}